This project will result in the development of improved measures of health related quality of life (HRQOL) for veterans with post traumatic stress disorder (PTSD). Because our work will be built on and linked to work of larger national HRQOL projects, the results will not only improve measurement for veterans with PTSD but will also allow for comparison of results across clinic settings and disease groups. We will develop and validate a short form of the measure that will enable using it with traditional self-administered techniques. In addition, algorithms will be created to facilitate the adaptation of the resultant measures into a computerized adapted testing (CAT) environment, which will streamline the use of the tool in clinical practice and reduce respondent burden. While the primary outcome measure used to test the efficacy of clinical interventions in PTSD is the reduction of symptoms, increasingly measures of health related quality of life (HRQOL) are also included. The most commonly used HRQOL measure employed in clinical studies of veterans with PTSD is the Medical Outcomes Study Short Form Health Survey (SF-36). The SF-36 is a generic HRQOL instrument that does not contain specific domains/items reflecting quality of life issues experienced by veterans with deployment-related PTSD. The goal of this study is to design more sensitive measures of deployment-related PTSD HRQOL for veterans that do contain such items/domains. The short term objectives of this study are to: 1) Identify the most important HRQOL issues, concerns and subsequent domains/constructs (e.g. distress, pain, social role changes) that a HRQOL measure should assess in Veterans with deployment-related PTSD. 2) Develop new items pools and/or adapt item banks from existing NIH funded tools (e.g., PROMIS/Neuro QOL) that represent unidimensional domains/constructs that address the unique issues facing Veterans with deployment-related PTSD. 3) Field test newly created and adapted item pools with a sample of Veterans with deployment-related PTSD. 4) Use Item Response Theory (IRT) methodology to calibrate item banks measuring the domains/constructs to support the development of computer adaptive testing (CAT). 5) Create short forms from the calibrated item banks for use with Veterans with deployment-related PTSD. 6) Conduct a Classic Test Theory-based validation study of calibrated short forms to examine convergent/concurrent validity, internal consistency reliability, and test-re-test reliability. This three-year prospective study will employ a mixed methods research design in three phases. In Phase 1 of the study, focus groups of patients and providers will be used to see how post deployment- related PTSD issues are underrepresented in PROMIS/Neuro-QOL. This qualitative data will serve to confirm or refute the importance of each PROMIS/Neuro-QOL domain/construct, to supplement the existing conceptual structure with post deployment-related PTSD specific areas of interest, and to flesh out the detailed constructs of HRQOL that are particularly relevant for this population. In Phase 2, both the existing HRQOL item banks and the new item pools targeted at the unique nature of deployment- related PTSD will be field tested in a large sample of veterans. In Phase 3, psychometric analysis of the field test data will be conducted based on IRT, a short form of the item banks will be developed, and algorithms for future development of a computerized adaptive test (CAT) will be created.